As a core component of optical (e.g., fiber-optic) communications networks, optical transceivers have provided optical data transmission systems with low cost, large capacity, and low power consumption. Such transceivers make fiber-optic networks more complete, smaller, and can increase access to the transceiver interface board. Such transceivers comprise optoelectronic component(s), functional circuitry, a laser and a photodiode-transimpedance amplifier (PIN-TIA), in which the optoelectronic component(s) include both transmitter and receiver circuitry. In some embodiments, the transmitter circuitry comprises a light-emitting diode (LED), a vertical-cavity surface-emitting laser (VCSEL), Fabry-Perot circuitry (FP), and/or distributed feedback (DFB) and electro-absorption modulated laser (EML) circuitry. Additionally, the receiver circuitry can comprise a p-type/intrinsic/n-type photodetector (e.g., a PIN photodiode) and/or an avalanche photodetector (APD).
Conventional high-capacity, long-range, high-speed transceivers utilize a cooled EML laser and laser driver. However, such lasers and drivers consume large amounts of power, thus making it difficult to reduce power consumption. Additionally, with the high power consumption required by temperature controllers available on today's market, such controllers are especially inefficient for cooling devices under low current conditions, thus increasing the power consumed by the entire transceiver. For example, in an SFP+ transceiver (which are transceivers configured to operate at speeds faster than those of SFP transceivers), in which an EML laser driver is utilized to drive an EML laser, the EML laser can consume large amounts of power.
In such a receiver, to ensure that the laser functions properly at any given temperature within a given temperature range, the temperature of the EML laser is set to a temperature (e.g., TEML) within a given temperature range, and subsequently adjusted by cooling (if the laser is at a higher temperature) or heating (if the laser is at a lower temperature). The greater the temperature difference between TEML and the given temperature, the greater the cooling or heating required to obtain the temperature TEML, and thus, the more power consumed.
Additionally, in certain conventional embodiments, a direct current (DC) from a MOS transistor (e.g., a MOSFET) is used as an input bias current to the EML laser, and a current-limiting resistor (which itself consumes power) is connected in series between the MOS and EML laser to limit current. Furthermore, even when a voltage is directly supplied, it can be difficult to reduce transceiver power consumption.
The technical solutions above are all causes of high power consumption related to conventional SFP and SFP+ transceivers (i.e., SFP transceivers capable of operating at high data rates), as well as other similar optical transceivers which may benefit from low power consumption solutions. The present invention overcomes the shortcomings of the conventional technology, and provides a long reach, low power consumption, pluggable transceiver configured to effectively reduce power consumption.